Progressive variable speed drive capable of reverse rotation



Sept. 29, 1953 2,653,490

E. TESTORI PROGRESSIVE VARIABLE SPEED DRIVE CAPABLE OF REVERSE ROTATIONFiled May 29, 1951 2 Sheets-Sheet 1 IN V EN TOR: EDUARDO Tasman,

ziAA/Y Sept. 29, 1953 E. TESTORI 2,653,490

PROGRESSIVE VARIABLE SPEED DRIVE CAPABLE OF REVERSE ROTATION Filed May29, 1951 2 Sheets-Sheet 2 IN V.EN TOR: EDOARDO TEsTom,

HIS AGENT:

Patented Sept. 29 1953 CAPABLE lldoarcio lestori, Milan, ItalyKiipiiatibh Mavis, 1951,,Spria], No. 228,866

"InItaly"Januafy2'4,1951

s V. l "The present inventionf concerns a progressivevariablespeeddrivefby 'whi'ch'it i's 'eveirpossibl'e t'o' reach. a 'zero'speed on the 'drivenishaft, while "the driving shaft rotatesht anywhatever speed, and whichallows a'ls'oito'reverse thefdirectionpfrotation. ;One of the advantages of this variable ispeeddriveis thatsame" is vlery'simple; in construction gives a verygoodperfoi'mance,andis of lyeryrompact.designfsojias tolen'd itself advantageo'uslyiorlall; thosei. applications, where it is wanted to obtain.aiproeressiv adjust b e pee variation, from a positive maximum to anegative maiciiii'u'ih.

The variable speed drive according to the inai ea s se ta ier a llfactha 9. the driving shaftthgreisfi "atwg m racket each end of which isfast 'witha shaft cal rying rigidly at one. side a variable transmissionmembenapt lo, ibeilcoupled with. a .similar, aligned imember mounted onthe other shaft, symmetrical to the first one, and at the other side agear wheel, one of these gears meshing with a stationary central gearfixed on the frame, and about which the assembly rotates with aplanetary motion, while the other gear meshes with a gear fast with thedriven shaft, that is mounted coaxially and internally to said centralstationary gear, there being provided a device apt to vary thetransmission ratio between the two variable transmission members coupledto each other, during the operation of the whole unit.

In one of the possible practical embodiments, the two variabletransmission members can be constituted by two adjustable grooveV-pulleys. It is however obvious that these pulleys may be eventuallysubstituted by other members such as gear wheels and the like, providedwith devices allowing to vary the transmission ratio during theoperation of the drive unit.

The accompanying drawing represents diagrammatically by way of anexample a form of embodiment of the present invention and namely:

Fig. 1 is a schematic side view of the variable speed drive;

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1, and

Fig. 3 is a large-scale fragment/ ary sectional View taken on line 3-3of Fig. 2.

As it is apparent from the drawing, the variable speed drive comprises adriving pulley I, keyed on the driving shaft 2, that carries at itsother end a two arm bracket 3, the end 3' whereof forms a journalbearing for a shaft 4, carrying at one end an adjustable sheave 5, andat its other end a gear wheel meshing with a central stationary gear I,mounted fast on the transmission frame ire-sins. (or m cso) f3k y'euon-tntfiaor-sriare I4;jourrrall'ed 'onthe 'oth'er"'erid *3 "of "the twoarm" 'braket "3. This shaft' I 4 carries "at "its end oppositethe'-o1fe"carr'ying'gear'WheeI t3; the 'otlierz'idjustablasheaiie 15,which is aligned with "the first-adjustable :sheave 155,!1'1o1ihtd on"the -o t-h,er *en'd -34 of the bracketli. 'In this form embodiment-magn"ingshaft'z and the driven-shaft lq ar asserrrble d coaxially endwise,and a projection lion shaft l0 con titut a i eerun aeip vqti p etest in, or er ova he ra i sive ra a eiw en -th two sliu ta les ia sli an.!L.. fi. 7 1 ipr vid ahpl ow. sa is in iders. see q s .snieel fi.Wilhua l est .....s. sw;ihre i i i to engage in the correspondingscrew'tliread firovided on the inside of shaft 4. The end of spindle l6,situated on the same side as the adjustable sheave 5 carries a yok llhaving the purpose of acting on one of the sides of sheave 5 so as topush it away from the other side, thereby allowing the V-belt I8 topenetrate further inside, thus reducing the operating radius, thereofwhich instead is correspondingly increased on the other adjustablesheave l5, that is subjected to the action of a spring [9. The spindlel6, passing through the hollow shaft 4, carries at its other end a gearwheel 20 meshing with a second gear wheel 2| assembled freely rotatableon the stationary shaft 9, whereon is rigidly mounted the centralstationary gear I. Gear wheel 2| is provided with control levers 2222'that allow to angularly vary its position. This angular adjustment istransmitted to gear 20 and consequently to the spindle l6, which bymeans of its screw thread 23 causes the lateral spreading of one of thesides of the adjustable sheave 5. The central gear 2| carrying the twolevers 2222' for controlling the variation of the transmission ratiobetween sheaves 5 and l 5, has the same diameter as the centralstationary gear 1. Gear Wheels I2 and I3 too have the same diameter.

While the parts of the device are shown in a schematic way in Fig. 1,their actual shape and positioning have been illustrated in Fig. 3.

The operation of the variable speed drive is as follows:

The rotation of pulley l and shaft 2 is transmitted through bracket 3 togear wheel 6, that rotates in a planetary way about the centralstationary gear I, carrying in rotation the assembly of sheaves 5 and I5, between which there is a predetermined transmission ratio, controlledby means of levers 2222, gear Wheels 2| and 20, and spindle I6.Consequently, sheave |5 wi1l run at a certain speed that is transmittedto gear wheel I3 and from same to gear wheel 12 and the driven shaft In.It is apparent that, by suitably varying the transmission ratio betweensheaves 5 and I5, it will be possible to even attain a zero speed onshaft :0, and further, also a reversal of rotation.

It is apparent that the arrangement illustrated and described forobtaining the variation of the transmission ratio between sheaves 5 and15 may be substituted by other equivalent mechanical devices.

What I claim is:

1. In a variable speed drive including a frame, in combination, adriving shaft and a driven shaft journalled on said frame andtransmission means therebetween comprising a two-armed lever secured onsaid driving shaft and rotatable therewith, a rotatable auxiliary firstshaft journalled in one arm of said lever, a rotatable auxiliary secondshaft journalled in the other arm of said lever, said auxiliary shaftsbeing revoluble in planetary rotation each about its own axis and aboutsaid driving shaft, a gear secured on each auxiliary shaft and rotatabletherewith, a stationary pinion fixed on said frame and being in meshwith the gear of said first shaft, whereby shaft at variable speeddepending on the position of said movable parts of said pulleys, a,pinion mounted on said driven shaft and in mesh with said gear of saidsecond shaft to be turned thereby, a mechanism connected to the movablepulley part of said first shaft and actuable to move said part foradjustment of the pulley thereof to change the position of the belt forspeed transmission variation, and resilient means con nected to themovable part of the opposite pulley urging the pulley to hold the beltin a normal position and to yield for belt support in all beltpositions.

2. In a variable speed drive, as claimed in claim 1, said first shaftbeing hollow and having a thread formed on its interior, said mechanismcomprising a screw disposed in said hollow first shaft and engaging thethread thereof and being turnable for movement axially of said firstshaft, means on one end of said screw and connected to said movable partof the pulley of said first shaft, a control gear connected to saidscrew, and a freely turnable control pinion mounted on said frame and inmesh with said control gear, said gears of said first shaft and screwbeing co-axial and having the same size, and said pinions on said framebeing co-axial and having the same size, whereb said control pinionduring operation of the drive will normally be at rest and turning ofsaid control pinion will turn said screw to adjust the pulley of saidfirst shaft.

EDOARDO TESTORI.

Name Date Locke Oct. 21, 1941 Number

